Binder jetting is an additive manufacturing technique based on the use of a binder to join particles of a powder to form a three-dimensional object. In particular, the binder is jetted from a printhead onto successive layers of the powder in a build volume, where layers of the powder and the binder adhere to one another to form a three-dimensional object. Through subsequent processing, such as removal of the binder from the three-dimensional object, the three-dimensional object can be formed into a finished part.
In general, however, the quality of the finished part may be impacted by unintended movement of the powder during layer-by-layer formation of the three-dimensional object or by subsequent processing of the three-dimensional object to form the finished part. For example, as the binder is jetted from the printhead into the build volume, the impact of droplets of the binder on the particles of the powder in the build volume may cause ejection of powder particles from the build volume. The ejected particles, and some small amounts of binder carried with the ejected particles, can redeposit on the printhead, clogging orifices or otherwise degrading the printhead, including by changing the wetting conditions on the outlet of the printhead. Such degradation of the printhead may compromise accuracy of placement of the binder along the powder in the build volume, thus producing defects in the three-dimensional object, and ultimately in the finished part, formed from the three-dimensional object.
Accordingly, there remains a need for managing powder mobility during binder jetting processes for additive manufacturing of three-dimensional parts.